Angle-independent microwave absorption by ultrathin microcavity arrays

The resonant absorption of microwave radiation by thin, two-dimensional microcavity arrays has been studied. Resonant modes associated with these structures, formed from copper-clad FR4 laminates, exhibit both an azimuthal and polar angle independent electromagnetic response. The experimental data agree well with the predictions of a finite element method computer model, which has been utilized to explore the electromagnetic character of the resonant modes supported.